(1) Field of the Invention
The present invention relates generally to implantable medical devices, such as of the types for monitoring physiological parameters. More particularly, the invention relates to an anchor for a medical implant, a method of manufacturing anchors, and a method of placing a medical implant, wherein the anchor and method are suitable for use in procedures performed to diagnose, monitor, and/or treat cardiovascular diseases, including procedures performed to monitor pressure in the left side of the heart.
(2) Description of the Related Art
Congestive Heart Failure (CHF), a condition in which the heart fails to pump efficiently, currently affects about 4.7 million patients (over 400,000 new patients per year in the U.S.), accounts for about 5 to 10% of all hospitalizations, and costs over $38 billion in the U.S. Following diagnosis of congestive heart failure, physicians typically monitor disease progression on a continuing basis to better tailor treatment. The best course of action for a tailored treatment involves monitoring of the pressures of the left side of the heart, particularly left ventricular end diastolic pressure (LVEDP, also known as left ventricular filling pressure) and mean left atrium pressure (MLA). These pressures are recognized as the best parameters for characterizing congestive heart failure in patients. Clinical evaluation of LVEDP or MLA is currently limited to a cardiac catheterization procedure, which provides a snapshot of pressure data a few times per year at most, carries morbidity, and is expensive.
Monitoring the pressures of the left side of the heart is a very challenging task for many reasons, most importantly the potentially fatal outcome of any thrombi caused by the implant. Implants can be made using many technologies, though preferred methods typically include MEMS (Microelectromechanical systems) devices and technologies. Such miniaturized implants can provide chronic, continuous bio-pressure measurements and support the trend toward home health monitoring. Pressure monitoring systems have two primary components: the implant comprising an implantable telemetric pressure sensor that is batteryless or makes use of a small battery, and a companion hand-held reader. The implant further includes custom electronics for processing the output of the sensor and an antenna for telemetry and, if necessary or desired, for tele-powering the sensor. Telemetry and tele-powering can be achieved via various techniques, including but not limited to magnetic telemetry (including RF), acoustic waves, ultrasonic waves, with the currently preferred technique typically being magnetic telemetry. The reader transmits power to the sensor, and the sensed pressure is in turn transmitted back to the reader. Data collected from the sensor can then be used by a physician to tailor the treatment of the patient. In some cases, the implant may also be configured or adapted to perform additional functions, such as delivering a drug or an electric signal to the muscles/nerves.
Though the above evidences that significant advances have been achieved for implants capable of diagnosing, monitoring, and/or treating cardiovascular diseases, further improvements are desired, particularly pertaining to the delivery and anchoring of such medical implants within the heart for monitoring heart pressures.